Extend AWS EBS volume with LVM installed

Yes, I know that there is the documentation for this, but I found it not clear enough on the Volume Extend topic. What I wanted to do was to change the size of my LVM volume from 128GB to 378GB (don’t ask).

I started with the creation of a snapshot (just in case something went wrong) and extending the EBS volume size in the AWS console, which is clearly explained in the documentation.

Once the volume was resized in the AWS console, the result of the lsblk command was as follows:

$ sudo lsblk
[...]
nvme2n1           259:3    0  378G  0 disk
└─vg--srv-lv--srv 253:0    0  128G  0 lvm  /srv
[...]

In the AWS LVM volume extending documentation, you may read that you should use growpart. So, this is the part that took me some time. With nvme volumes there is no such need. You should go straight to pvresize which in my case was:

$ sudo pvresize /dev/nvme2n1
  WARNING: PV /dev/nvme2n1 in VG vg-srv is using an old PV header, modify the VG to update.                                                                                                                                                    
  WARNING: updating PV header on /dev/nvme2n1 for VG vg-srv.
  Physical volume "/dev/nvme2n1" changed
  1 physical volume(s) resized or updated / 0 physical volume(s) not resized

I also executed pvs, vgs, and lvs to see if everything is fine:

$ sudo pvs
  PV           VG     Fmt  Attr PSize    PFree                                                                                                                                                                                                 /dev/nvme2n1 vg-srv lvm2 a--  <378.00g 250.00g

$ sudo vgs
  VG     #PV #LV #SN Attr   VSize    VFree
  vg-srv   1   1   0 wz--n- <378.00g 250.00g

$ sudo lvs                                                                                                                                                                                                    LV     VG     Attr       LSize    Pool Origin Data%  Meta%  Move Log Cpy%Sync Convert                                                                                                                                                        lv-srv vg-srv -wi-ao---- <128.00g

Looks like we have added 250G of free space, let’s extend the volume using lvextend. What I will need for this, is the VG and LV values from the lvs execution above. My command looked like this:

$ sudo lvextend -L 378G /dev/vg-srv/lv-srv                                                                                                                                                                    Insufficient free space: 32768 extents needed, but only 32767 available

Whoops, looks like a little bit too much, so (because I had no time to calculate it) I simply took one GB less:

$ sudo lvextend -L 377G /dev/vg-srv/lv-srv                                                                                                                                                                    Size of logical volume vg-srv/lv-srv changed from 128.00 GiB (32768 extents) to 377.00 GiB (96512 extents).

Now my lsblk looks like this:

$ sudo lsblk
[...]
nvme2n1           259:3    0  378G  0 disk
└─vg--srv-lv--srv 253:0    0  377G  0 lvm  /srv
[...]

Nice, but this is not the end. When you take a look at the df result, the volume available for the system is still not resized:

$ df -h 
[...]
/dev/mapper/vg--srv-lv--srv  126G  104G   17G  87% /srv
[...]

Because my volume is using Ext4, the last command was:

$ sudo resize2fs /dev/vg-srv/lv-srv
resize2fs 1.45.5 (07-Jan-2020)
Filesystem at /dev/vg-srv/lv-srv is mounted on /srv; on-line resizing required
old_desc_blocks = 8, new_desc_blocks = 24
The filesystem on /dev/vg-srv/lv-srv is now 98828288 (4k) blocks long.

Note that I again used the VG and LV values from the lvs command result. Now the work is finished:

$ df -h
[...]
/dev/mapper/vg--srv-lv--srv  371G  104G  252G  30% /srv
[...]

Instead of resizing the existing volume, in case you are using LVM you can add a new one and join two “physical” volumes in one “logical” volume. It brings a new one in the volume group with the old one. Since I never did this before, I will not try to do it now 🙂

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